Physics, Astronomy, Optics and Photonics
Gold Ring and Graphite-Based Plasmonic Photonic Crystal Sensor for Biomedical Applications
This research puts forward a cost-efficient high-efficiency plasmonic photonic crystal sensor for biomedical applications that functions in the near-infrared range.
The sensor design is composed of multiple two-dimensional photonic crystal layers stacked in the order of SiO2 foundational layer graphite layer MgF2 waveguide and finally a gold ring over the top. The graphite layer is deposited for optimum sensing and high absorption peaks and is state-of-the-art in this research work. Metal deposition of the gold layer is used for harnessing plasmonic properties that play a vital role in detecting small refractive index changes.
The sensor design is investigated for a range of coupling incident angles and it is found that the sensor is responsive to a broad range of angles i.e. 0o to 80o. The proposed sensor has given output peak values of more than 90% in the whole range of incident source angles.
Finally water and 25% concentration of glucose samples are used for investigating sensor performance and it is noted that the sensor’s sensitivity reaches as high as 1675 nm/RIU-1 with a Figure of Merit (FOM) of 20.94 RIU-1. The sensor’s numerical simulations have been performed using Finite Element Method (FEM) and Finite Difference Time Domain (FDTD).
Classical Stark and Zeeman Effects of Axially-symmetric Circular Rydberg States of He and He-like Ions
Circular Rydberg States (CRS) were studied theoretically and experimentally in numerous works. In particular in the previous paper by one of us there were derived analytical expressions for the energy of classical CRS in collinear electric (F) and magnetic (B) fields of arbitrary strengths imposed on a hydrogenic system (atom or ion). For the magnetic field B of any strength the author of that study gave formulas for the dependency of the classical ionization threshold Fc(B) and the energy at this threshold Ec(B). He also analyzed the stability of the motion by going beyond the CRS. In addition for two important particular cases previously studied in the literature – classical CRS in a magnetic field only and classical CRS in an electric field only – some new results were also presented in that paper especially concerning the Stark effect.
In the present paper we study analytically axially-symmetric CRS of a heliumic system (He atom or He-like ion) subjected to an electric or magnetic field of arbitrary strength.
In this investigation analytical techniques were applied.
We showed that in the case of the Stark effect the difference in the unperturbed structure of the heliumic systems (compared to hydrogenic systems) i.e. the non-negligible size causes the decrease of the classical ionization threshold as well as increases the energy and the orbit radius of the outer electron at the ionization threshold. Also the allowance for the non-negligible size of the internal subsystem increases the maximum possible absolute value of the induced electric dipole moment. In the case of the Zeeman effect we demonstrated that the non-negligible size of the inner system increases the energy and the orbit radius of the outer electron.
The allowance for the non-negligible size of the internal subsystem can strongly affect the properties of the axially symmetric circular states. We believe that our results are of fundamental importance.
Aero-space and Astro-cosmic Microbial Studies: A Vulgar Epithet Yet an Unattended Potential Nursing/Distribution Hub of Pathogenic Strains
The ubiquity of microorganisms has in recent times extended relevance from the physical environment to outer space/cosmic environment. Such outer space/cosmic environments were over time reported microbe free however recent report showed otherwise implicating space/cosmic travel.
Diverse interest-based investigators have raised unanswered questions while others yet remain probable. Bio-scientific evaluation of astro-cosmic dynamics possesses the potential of revealing the appropriate status arrangement and/or position of microbes especially as global drives focus on controlling microbial spread/proliferation.
The study determines microbes in space and astro-cosmic environment as vulgar epithet yet an unattended potential nursing/distribution hub of pathogenic strains applying science mapping review tools. Using the Preferred-Reporting-Items-for-Systematic-Reviews-and-Meta-Analyses (PRISMA) major scientific databases (Scopus Web of Science and PubMed) were searched for required and related data on astro-cosmic studies. A 7-decadal evaluation of authors' published documents using the non-parametric ANOVA test (Kruskal-Wallis H test) and Lotka’s model was applied. Among the three searched databases Web of Science ranked least in retrieved documents (130) followed by PubMed (331) and Scopus (409) with total documents retrieved as 693 between 1954-2023. Further results revealed that production/publication distribution was significant only in the first decade using Lotk’s model with an annual growth rate of 5.23%. It was also observed that more than 40 topics of interest/conceptual thematic were trending in association with astro-microbiological studies.
A focus on these topics and their associated themes possess the potential for understanding the future position of the microbes in outer space the distribution of potentially pathogenic strains from outer space and necessitates global interest for such studies.
Gravity as a Screening Effect
A model of quantum gravity unrelated to general relativity is described. The main postulate of the model is the assumption of the existence of a background of superstrongly interacting gravitons. To describe the interaction of a graviton with any particle during their collision a new constant is introduced.
It is shown that screening of the background of single gravitons by a pair of bodies leads to approximately equal attractive and repulsive forces between the bodies. Pairing of a part of the background gravitons provided that the pairs are destroyed as a result of a collision with a body yields an attractive force twice as great as the repulsive force and gravity arises as an effect of background screening.
Newton’s constant has been calculated in the model as a function of background temperature which allows the value of the new constant to be estimated. This model is free from divergences unlike quantum gravity models based on general relativity due to the specific shape of the Planck spectrum of the graviton background. A theoretical estimate of the Hubble constant depending on the new constant is also obtained.
An important feature of the model is the necessity of an “atomic” structure of matter which leads as a side effect to the prohibition of the existence of black holes that do not have such a structure. Small additional effects of the model caused by the interaction of photons with gravitons may have great significance for cosmology.
A Novel Optical Diagnostic Tool for Fuel Characterization in the Spark Ignition Chamber
The Spark Ignition chamber plays a very vital part in internal combustion engines.
In line with this this short communication dwells upon a novel probing technique that employs high-speed cameras and a fiber endoscope-based particle velocimeter.
The flame propagation and combustion characteristics vary greatly depending on the fuel type and air mixture which can be examined using a variety of probing techniques.
The proposed scheme can give valuable information on flame propagation features fuel concentration and particle velocity which either way is able to optimize the performance of combustion engine
The addition of machine learning will ease the process of data acquisition as well as their effective management in enhancing the optimality of the internal combustion engine. It is envisioned that the novel design would pave the way for more research in this direction.
Parasitic Resistance Impacting Fill Factor of a GaAs Solar Cell
The efficiency of a photovoltaic cell is fundamentally determined by its maximum power output which is closely related to the fill factor. The fill factor which defines the shape of the I-V characteristics of a solar cell is influenced by various environmental and internal parameters. Among these parasitic series and shunt resistances (RSH) are two major factors that significantly affect the fill factor.
Numerical analysis was conducted to investigate the impact of parasitic series and shunt resistances on the I-V characteristics of a solar cell. The analysis focused on how these resistances influence the fill factor. For reference the highest recorded efficiency and other corresponding parameters of a GaAs (Multicrystalline) solar cell were used.
The results showed that as the value of RSH decreases the I-V curve flattens leading to a considerable decrease in the fill factor.
The observed flattening of the I-V curve and the subsequent decrease in the fill factor highlight the critical role of parasitic resistances in determining the efficiency of solar cells. Understanding and mitigating these parasitic effects can lead to significant improvements in the performance of GaAs solar cells.
The findings from this numerical analysis provide valuable insights into the impact of parasitic resistances on the efficiency of GaAs solar cells. These results are expected to guide future implementations aimed at enhancing the efficiency of GaAs solar cells.
Creation of Technology and Devices for the Preparation of Motor Fuels Containing Biocomponents
In the world active research is being conducted to create motor fuels containing bio-oil as a component derived from renewable environmentally friendly sources of raw materials such as wood processing waste agriculture marine algae etc. One of the most commonly used technologies for bio-oil production is fast pyrolysis. Due to the physical and chemical properties of such bio-oil direct blending with petroleum motor fuel is not possible.
The goal of the conducted research was to develop technology and devices to address this issue. Fundamental developments in the field of nonlinear wave mechanics formed the basis for these endeavors.
During the research designs for motor fuel preparation devices were developed and mathematical modeling of the mixing processes of fuel components was carried out. The obtained data were analyzed and transferred to natural samples which were examined during experiments.
As a result blended fuels based on bio-oil (up to 15% by weight) and diesel fuel (marine) with stability of up to 10 days without the use of surface-active substances (SF) and 25-30 days with the addition of SF (up to 0.5% by weight) were obtained.
Fuel containing SF is re-homogenized by traditional stirring for at least 3 months. The obtained results confirmed the correctness of the chosen approach and the feasibility of using the developed technology for preparing blended motor fuel containing bio-oil.
Medical Physics and Technics for Optimizing Imaging of Wounds
The relevance of modernity can include both a huge number of physical injuries to people and a large number of methods of their diagnosis that have appeared in medical physics.
A narrative review of the use of modern physical imaging methods in the diagnosis of gunshot and mine-explosive wounds was conducted to develop algorithms for choosing optimal methods and devices for medical diagnostics.
After a comparative analysis of localization and physical characteristics of tissues and damaging elements algorithms have been developed in the form of a matrix table “wound localization - physical visualization methods” for the specific purpose of special adequate qualitative and effective diagnostics.
Development-synthesis of a prospective methodology for choosing optimal methods and devices for medical diagnostics compression of verified information in the form of a locus-method algorithm can contribute to the speed and optimality of choosing effective diagnostics using medical physics methods as well as strategic planning for the acquisition and organization of special instrumentation in healthcare systems.
A LC-MS/MS Approach for the Identification of Degradation Products of Serdexmethylphenidate and Dexmethylphenidate and Elucidation of their Degradation Pathway
A combination of serdexmethylphenidate and dexmethylphenidate are used to treat attention deficiency hyperactivity disorder. A stability-indicating RP-HPLC method has been developed and reported in the literature. As there is no study on the degradation product identification in this work the degradation behavior of serdexmethylphenidate and dexmethylphenidate was explored by subjecting combined dosage to the forced degradation study by applying the developed RP-HPLC method. Further plausible structures and fragmentation patterns of all the degradation products were identified by the LC-MS/MS study.
The forced degradation study was conducted by exposing the combined dosage form (Azstarys) as per International Council of Harmonization (ICH) guideline Q1A (R2). Using LC-MS/MS MS spectra were obtained. Based on the m/z values and molecular formula probable structures of degradation products were elucidated.
A total of 7 degradation products were detected of which 4 degradation products were formed from serdexmethylphenidate. The remaining 3 degradation products were formed from dexmethylphenidate. The possible structures and fragmentation patterns of all the degradation products were examined with the help of the LC-MS/MS study.
As possible structures and fragmentation patterns were identified by the LC-MS/MS study this method may help in the development of quality dosage forms maintaining proper storage conditions and also in impurity profiling studies.
Advanced Uses of Liquid and Gas Chromatography: Impact Across Industrial and Scientific Research
Chromatography is a very useful separation method that may be used for characterization isolation/purification and chemical and nanoparticle analysis. It has completely changed how many industries do research and development. This comprehensive study looks at its increasing importance in nanotechnology and its applications in the fields of biological sciences pharmacology environmental science and industry. In the pharmaceutical business chromatography is used to detect contaminants guarantee drug quality and support pharmacokinetic research. It evaluates pesticide residues finds poisons in environmental assessments and identifies contaminants in the air and water. Chromatography is employed in forensic science for drug testing examination of trace evidence and arson investigations. Chromatography is used in the food and beverage industries for quality control and taste profiling and in the life sciences for protein separation and identification. Chromatography is used in biological research for the separation of complex mixtures and the purification of biomolecules. It is used in the industrial sector to assess petroleum products evaluate the quality of cosmetic chemicals and describe polymers. Because it enables the separation and analysis of nanoparticles for use in synthesis characterization and nanotechnology chromatography is also becoming more and more popular in this sector. This article emphasises chromatography's enormous influence across a number of sectors as well as its developing importance in nanotechnology. Chromatographic techniques will continue to advance and change paving the way for fresh investigations and altering the landscape of academia and business.
A Comprehensive Review on High-Performance Liquid Chromatography and Hyphenated Techniques for Analysis of Centrally Acting Skeletal Muscle Relaxants
This review provides a comprehensive overview of the analytical approaches used for the evaluation of centrally acting skeletal muscle relaxants through the application of High-Performance Liquid Chromatography (HPLC) and associated techniques. This analysis includes the evaluation of drugs in their pure form in pharmaceutical formulations and in human plasma or other biological fluids. A literature search was conducted focusing on a specific group of centrally acting skeletal muscle relaxants such as Carisoprodol Tizanidine Chlorzoxazone Diazepam Clonazepam Methocarbamol and Baclofen. The review summarizes the application of HPLC and Ultra-Fast Liquid Chromatography (UFLC) techniques integrated with UV spectrophotometric detection and mass spectrometric refraction (LC-MS/MS) to facilitate the quantification of the above drugs. Furthermore the validated process of analytical techniques focuses on parameters such as linearity range recovery Limit of Detection (LOD) and Limit of Quantification (LOQ) to ensure reliability and precision in drug concentration evaluations. This knowledge can be utilised in further research and development which ultimately leads to improved patient care and treatment outcomes.
Application of Thin Layer Chromatography in Determining the Natural Diversifications of Phytochemicals in Rubia cordifolia
Geographical location plays a crucial role in the distribution and potency of medicinal plants. Chemical composition of plants and their medicinal properties can be significantly influenced by climate and soil composition. The present objective is to investigate the manifestation in phytocompounds of Rubia cordifolia L. root originating from different biogeographical locations in the Indian subcontinent. R. cordifolia is traditionally used to treat chronic pyrexia and puerperal fever along with reducing the heat and itching in various skin diseases. Other therapeutic benefits include immune-modulatory analgesic diuretic hepatoprotective nephroprotective gastroprotective wound-healing and antiviral properties.
This study establishes a qualitative profile and analyzes the amount of rubiadin in the root of Rubia cordifolia L. across four different biogeographical zones by using a reproducible and validated HPTLC method.
The study revealed phytochemical arrays are not identical for plants of different zones and that the quantity of rubiadin was highest (0.73%) and lowest (0.27%) in the plants grown in the Deccan Plateau region and northeast region respectively.
The study demonstrates that the Indian subcontinent boasts a rich tapestry of biodiversity and this diversity is reflected in the array of phytocompounds found across its various biogeographical regions mainly due to climate and soil characteristics.
This information can be valuable for applications in agriculture pharmaceuticals and environmental studies because understanding the distribution and concentration of phytocompounds across different locations can have numerous applications in these fields.
Validated RP-HPLC Method for Simultaneous Estimation of Tadalafil and Macitentan in Bulk and Dosage Forms
Reverse-phase high-performance liquid chromatography is a simple quick accurate sensitive and reproducible technique for quantitatively analyzing Tadalafil and Macitentan in pharmaceutical dosage form. This method is novel as it allows for the simultaneous quantification of both Tadalafil and Macitentan in a single run which is not widely reported in existing literature.
Waters Alliance-e2695 was used to perform the chromatographic separation of Tadalafil and Macitentan using an Agilent Eclipse XDB C18 (150 x 4.6 mm 3.5 µ) column and a mobile phase that contained acetonitrile: 0.1% TFA in a 50:50% v/v ratio. At room temperature the flow rate was found to be 1.0 ml/min and a photodiode array detector was used to monitor the absorption at 301 nm.
For Tadalafil and Macitentan the theoretical plate count was not less than 2000 and the tailing factor should not exceed 2. All measurements have a percentage relative standard deviation of peak areas that is consistently smaller than 2.
The suggested approach was validated in compliance with ICH Q2 (R1) regulations. This method was deemed simple cost-effective accurate precise and reliable for quantitative analysis of the stability study of Tadalafil and Macitentan. The novelty of this work mainly depends on the use of specific mobile phase composition pH column type or detection wavelength that achieves excellent separation and peak resolution within a shorter run time.
This study shows excellent sensitivity with low LOD/LOQ values and superior efficiency through rapid analysis good resolution and robustness making it suitable for routine quality control and pharmaceutical analysis.
Integral UV Spectrophotometric Method for the Determination of Loperamide Hydrochloride in Industrial Equipment Cleaning Rinse Waters
Loperamide is a widely produced generic medication included in the WHO list of essential medicines. Analysing trace amounts of the drug on the surfaces of equipment and in industrial cleaning rinse waters is crucial in pharmaceutical manufacturing. This paper presents a method for measuring loperamide hydrochloride in industrial equipment rinse waters using multiwavelength derivative UV spectrophotometry and the calculation of areas under the curves.
Spectra were obtained in an aqueous solution without prior adjustments to the pH. The spectra were numerically integrated over the wavelength range of 218 to 238 nm. The quantification of loperamide is conducted through the use of a regression equation.
The technique allows for the measurement of loperamide hydrochloride in solution within the concentration range of 1-60 mg/L with a limit of detection of 1.9 mg/L and a limit of quantification of 5.8 mg/L. The relative uncertainties are not greater than 3% for the analysis of solutions from active pharmaceutical ingredients and not greater than 7% for the analysis of model rinse waters. The relative standard deviations are up to 3% for solutions from active pharmaceutical ingredients and up to 7% for model rinse waters.
The analytical performance of the method is comparable to existing methods of spectrophotometric analysis of loperamide. The advantages of this method are that it requires minimal sample preparation does not use toxic organic solvents and does not involve complex analytical instrumentation making it suitable for the routine analysis of loperamide in rinse waters from industrial equipment cleaning.
The spectrophotometric method of determination of loperamide hydrochloride in aqueous medium using the derivative spectroscopy and the area under the curve method is proposed for the analysis of the rinse waters from industrial equipment cleaning.
Quantum-mechanical Explanation of Young’s double Slit Experiment through Simulation of the Photon Coordinate Wave Function
In the rapidly developing areas of photonics associated with quantum teleportation of photons quantum cryptography and quantum computing ideas are becoming increasingly relevant about the certain localized states of single or several entangled photons moving in space and time. As is known in quantum mechanics localized states of particles can only be described using wave functions in coordinate representation – the corresponding wave packets.
To explain Young's one- and two-photon experiments using coordinate 6-component quantum mechanical and 1-component quasi-classical photon wave functions.
The article outlines the method developed in authors' previous work in constructing the 6-component coordinate wave function of free photons in the form of the wave packet (an integral over the entire momentum space and sum over two possible values +1 and -1 of the helicity). The basis functions are the circularly polarized monochromatic waves corresponding to certain values of the momentum helicity and photon energy operators and forming a complete orthonormal set of generalized eigenfunctions of these operators. This photon wave function (PWF) is normalized to the unit probability of finding the photon anywhere in space. Both the basis functions and the coordinate PWF satisfy a Schrödinger-type equation derived from the Maxwell-Lorentz equations written in quantum mechanical form first introduced by Majorana. Then the results of modeling and consideration of the space-time evolution of the wave packet with Gaussian momentum distribution corresponding to the directed photon emission for 80 fs are briefly presented. Further in view of the possibility of constructing the coordinate PWF the basic formula for the wave-particle duality of photons and particles is formulated. It is emphasized that the photon is fundamentally different from “ordinary” particles since according to the authors the photon is the result of the propagation of a certain complex spin wave in a physical vacuum the details of which can only be considered simultaneously with the study of the structure of the physical vacuum at Planckian distances.
Young's one- and two-photon experiments are explained using various options for modeling 6-component coordinate PWFs including approximate functions corresponding to spherically symmetric and electric dipole photon radiation.
This explanation is illustrated using specific examples of radiation and at the same time is compared with numerical simulations for spherically symmetric radiation and the use of 1-component quasi-classical PWFs.
Carbamazepine Uptake and Metabolization by Lavandula Dentata, Juncus Sp., and Salicornia Europaea
Software has been used to predict metabolic pathways for possible ‘expected’ and ‘unexpected’ metabolites based on their m/z and fragmentation patterns from low- and high-fragmentation mass spectra of plants subjected to carbamazepine uptake has been used.
Three plants with high prevalence in the natural protected area of Doñana National Park (Spain) were irrigated with three aqueous carbamazepine solutions (10 ng‧mL-1 700 ng‧mL-1 and 10 μg‧mL-1). Periodically stems leaves and roots were sampled and analyzed. Total carbamazepine uptake throughout the assay was evaluated and discussed demonstrating a clear dependence on plant species/part irrigation solution concentration and assay duration. Additionally chromatographic analysis was performed using a quadrupole time-of-flight (Q-TOF) mass spectrometer recording simultaneous low and high-fragmentation mass spectra for further computational processing with MetabolynxTM software.
Confirmation was achieved by analyzing the high-energy spectra obtained at the characteristic retention times and fragmentation pattern of each compound.
Several potential carbamazepine metabolites corresponding to various metabolic pathways were identified and where possible their relative abundances was discussed.
The use of computational tools like MetabolynxTM has proven to be useful for studies involving the identification of metabolites and/or the confirmation of metabolic pathways in the studied plants.